Glycosaminoglycan and surface glycoprotein syntheses by rat muscle fibroblast monolayers: response to solubilized bone matrix and effect of serum.
Glycosaminoglycan synthesis by muscle fibroblasts derived from neonatal rats has been studied using a sensitive radioisotope method. Feeding the cultures with serum-containing medium supplemented with 80 micrograms/ml of a solubilized bone matrix (SBM) preparation results in an initial enhancement of net glycosaminoglycan secretion and a later additional response, not seen in controls. A pronounced dilution of the specific radioactivity of secreted chondroitin sulfate characterizes the latter response. SBM-treated cultures (100 micrograms/ml) also demonstrate increased incorporation of radioactive glucosamine into a large molecular weight cell surface glycoprotein. SBM suppresses the growth rate and final cell densities at all serum concentrations tested. However, at similar cell densities, higher serum concentrations tend to minimize the relative stimulation of incorporation of radioactivity into the secreted glycosaminoglycans by SBM-treated cultures, compared to controls.
D000818:Animals; D001769:Blood; D001857:Bone Matrix / Q000502:physiology*; D002455:Cell Division; D002478:Cells, Cultured; D002809:Chondroitin Sulfates / Q000096:biosynthesis; D003470:Culture Media; D005347:Fibroblasts / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis*; D006025:Glycosaminoglycans / Q000096:biosynthesis*; D006820:Hyaluronic Acid / Q000096:biosynthesis; D007700:Kinetics; D009132:Muscles; D051381:Rats
D003470:Culture Media; D006023:Glycoproteins; D006025:Glycosaminoglycans; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates